Add support for list, describe, and delete namespaces in grpc

[rohanshah18]

Problem

Support for REST sync and async namespaces was added in a previous PR, so this PR adds support for gRPC only.

Solution

Add support for list, describe, and delete namespaces in grpc.

from pinecone.grpc import PineconeGRPC as Pinecone

# Initialize Pinecone client
pc = Pinecone(api_key='your-api-key')

# Get index
index = pc.Index('your-index-name')

# Example: List all namespaces (automatic pagination)
print("All namespaces:")
for namespace in index.list_namespaces():
    print(f"{namespace.name}: {namespace.record_count} records")

# Example: List namespaces with pagination control
results = index.list_namespaces_paginated(limit=10)
print(f"First 10 namespaces:")
for namespace in results.namespaces:
    print(f"{namespace.name}: {namespace.record_count} records")

# Example: Describe a specific namespace
namespace_info = index.describe_namespace(namespace='my-namespace')
print(f"Namespace '{namespace_info.name}' has {namespace_info.record_count} records")

# Example: Delete a namespace (irreversible!)
index.delete_namespace(namespace='namespace-to-delete')

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Infrastructure change (CI configs, etc)
• Non-code change (docs, etc)
• None of the above: (explain here)

Test Plan

Added integration and unit tests

[austin-denoble]

LGTM, the one thing I noticed is we should probably delete the old 2025-01 grpc files since they're no longer being used, and I think we used to do this in the past:

• db_data_2025_01_pb2_grpc.py
• db_data_2025_01_pb2.py
• db_data_2025_01_pb2.pyi

[austin-denoble]

Interesting, I didn't realize the proto files weren't also generated for the v7 release initially. Do the 2025_01 files need to be removed as well? Currently, 2025-01 and 2025-04 are present and I don't think that's correct:

[rohanshah18]

Yeah, I don't have much context here on whether we delete the older versions or not, but it definitely feels weird not deleting 2025_01. In the future, I'd like to add the following steps to build-grpc.sh:

1. Before code generation: Delete old proto files.
2. After code generation: Either
   • Update all yyyy-mm references in the codebase so we don’t have to manually edit the imports, or
   • Rename the proto files to remove yyyy-mm, so no edits are required in the codebase.